Automatic differential expansion valve



161 ,129 Feb. 1,192,. GF'KNOX 5 AUTOMATIC DIFFERENTIAL EXPANSION VALVEFiled Feb. 19, 1923 2 sheets-Sheen Feb. 1, 1 927. 1,616,129

G. F. KNOX AUTOMATIC DIFFERENTIAL EXPANSION VALVE Filed Feb. 19, 1925 2Sheets-Sheet 2 az 31 W /.i"

INVENTOR. 1 92,

ATTORNEYS. 7

Patented Feb. 1, 1927.

UNITED STATES GEORGE F. KNOX, OF MILWAUKEE, WISCONSIN.

AUTOMATIC DIFFERENTIAL EXPANSION VALVE.

Application filed February 19, 1923;

This invention relates to a differential automatic diaphragm expansionvalve and particularly to a valve device of this type for use inconnection with a refrigerating system.

In refrigerating systems now employed, the refrigeration is accomplishedby means of ammonia gas and in this connection the invention about to bedescribed contemplates the provision of means for controlling thepassage of this ammonia gas through the refrigerating pipes.

The invention further contemplates the provision of means etl'eeted bythe temperature of the refrigerating system for controlling the ammoniagas valve and also includes the provision of means for balancing thevalves whereby a sensitive control is assured.

The various features of the invention will be made more apparent in theaccompanying specification and drzuvings wherein one illustrativeembodiment of the invention will be described and illustrated.

In the drawings:

Fig. 1 is an elevation of the valve control device, Y

Fig. 2 is a section taken on the plane indicated by line 22 in Fig. 1,and,

Fig. 3 is a vertical sectional view taken. .on the plane indicated byline 3-3 in Fi 1, certain parts being in elevation.

In the drawings wherein like reference characters indicate like parts,the reference character indicates a supply pipe for ammonia gas which isadapted to furnish the ammonia gas to the refrigerating system. Thissupply pipe is connected to a casing 11 and from this casing a dischargepipe 12 leads to the pipes of the refrigerating system.

Connecting the supply pipe 10 to the pipe 12 is a port 13 controlled bya needle valve 14, slidably mounted, the rear end of which bears againsta diaphragm 15 working in a diaphragm chamber 16. Also disposed withinthe casing 11 is a diaphragm 17 working in a diaphragm chamber 18.

Ports or passageways 19 provide communication between the passageway 13and one side of each of the diaphragms 15 and 17. A coil spring 20hearing against one end of the needle valve 14 and against the.

casing is adapted to move the needle valve 1% to open position whenpressure on the Serial No. 620,109.

opposite side of the diaphragm is less than the pressure or" the spring.

Mounted within-the casing 11 is a. lever 21 to which there is pivotallyconnected at each end short lever members 22 and 23 which bearrespectively against diaphragms 15 and 17. The short lever 23 is engagedby a spring 2a which is adapted to counteract the pressure of theagainst the opposite side of the diaphragm 17. The lever 21 is fulcrumedto a member 25 which bears against a diaphragm 26 positioned within adiaphragm chamber 27. A coil spring 28 urges the member 25 against thediaphragm 26 so that there is always an intimate contact between thediaphragm and this member. Screw-threadedly supported in the easing isan adjusting bolt 29 which bears against the diaphragm 26 opposite tothe member 25 and by which adjustment of the needle valve 1% isaccomplished.

For controlling the diaphragms and consequen-tly the needle valve, thereis provided a control chamber 30 formed with a diaphragm chamber 31 inwhich there is positioned a diaphragm 32. Through a passageway 33 thereis injected into the diaphragm chamber 31 ether or some other gas whichis highly sensitive to changes in temperature. This opening for theinjection of this fluid is closed by a plug 34 or the like. Bearingagainst one side of the diaphragm 32 is an adjustable plug 35 by whichthe pressure of the ether in the control chamber 31 is regulated. Thecontrol chamber 30 is connected to the casing 11 by a tube 36 providedwith a coil 37 and the end of this tube communicates with a passageway38 formed in the casing 11. Therefore, the ether or other fluid may passinto the casing 11 and past the right-hand side of diaphragm 28 aroundthe member 25 and into the portion of the casing in which the lever 21is positioned and then against the adjacent sides of the diaphragm 15and 17 It should be noted that the lever 21 is of greater length on oneside of its pivotal connection of the member 25 than on the other,thereby counteracting the influencing movements imparted to it.

The control chamber 30 will be positioned somewhere within therefrigerating plant so as 'to be influenced by changes in temperature.When the temperature of the refrigerating system has risen beyond adesired point, the ether or like gas Will expand against the diaphragm82 and hence pass through the tube 36, coil 37 and enter passageway 38'of the casing 11. The other will th refore exert a pressure against thediaphragms 15 and 17 and inasmuch as the diaphragm 17 is larger than thediaphragm 17 the pressure thus exerted will cause a movement of thelever 91 which will permit the spring 20 to move the needle valve itfrom its seat tl'iercby allowing a greater flow of ammonia gas throughthe pipes 10 and 12 to the pipes of the refrigerating system.

When the temperature of the refrigerator has again fallen to the properdegree, the ammonia gas will contract, thereby relieving pressure on thediaphragms l5 and 17 and permit a closing of the needle valve 14. Itshould be noted that as the ammonia gas passes through pipe l0,passageway 13 and pipe 12 that it acts upon the sides of the diaphragms15 and 17 opposite to those against which the ether gas is in contact.Furthermore. the position of the lever 21 will be regulated by theadjustii'ig bolt Which bears against the diaphragm so that the needlevalve will be caused to open upon a greater or less pressure of theether gas. Likewise the time at which the needle valve will function maybe regulated to some extent by the adjustment im iarted to adjustingbolt 35 which regulates the capacity of the chamber 31.

From the foregoing, it. will be obvious that I have provided a valvecontrol device which is sensitive to changes in temperature and whichwill accordingly control the valve governing the flow of therefrigerating fluid. Furthermore, by providing the diaphragms in themanner hereinbefore described, the de vice is capable of numerousadjustments whereby different conditions and degrees of telnpe 'aturemay be compensated for.

Having thus described this invention, What is claimed is:

1. In a differential automatic diaphragm expansion valve, arefrigerating fluid supply pipe, a valve for controlling said supply,differential diaphragms for influencing said valve, a control chambercontaining a thermostatic fluid. means for connecting said chamber tosaid differential valve, a difl erential lever pivoted between its endsand having its free ends bearing against said dif-- ferentialdiaphragms, means for positively adjusting the pivot of said lever, saidthermostatic fluid bearing against one side of said differentialdiaphragms, means for counteracting the pressure of said thermostaticfluid by the amount of refrigerating fluid passing through saidrefrigerating pipe whereby an expansion of said thermostatic.

fluid will cause said differential diaphragms to open said refrigeratingfluid control valve.

2. In a control device of the class described, a refrigerating fluidsupply pipe, a valve for controlling said supply, a pair of differentialdiaphragms, said differential diaphragms being subjected at one side tothe pressure of said refrigerating fluid, a control chamber containing athermostatic fluid, means for adjusting the capacity of said chamber,means connecting said chamber to the valve casing containingsaiddifferential diaphragn'is, said thermostatic fluid being conductedto the other side of said diaphragms, an adjustable differential leverhaving its free ends bearing against said diaphragms, and means foradjusting said lever, said thermostatic fluid operating upon saiddiaphragms to regulate said valve.

8. In a differential automatic diaphragm expansion valve, arefrigerating fluid therethrough. a pair of differential diaphragms,said differential diaphragms being influenced on one side by saidrefrigerating fluid. a differential lever mounted in the casing of saidvalve and engaging the opposite sides of said differential diaphragms,an adjustable means for regulating the fulcrum point of saiddifferential lever. a control chamber containing a thermostatic fluid,means for regulating the capacity of said control chamb r, means forconnecting said control chamber to said valve chamber, said thermostaticfluid acting against said differential diaphragms on the sides oppositeto those acted upon by the refrigerating fluid whereby an expansion ofsaid thermostatic fluid will cause said differential. diaphzigms tofunction for moving said differential lever and opening said valve.

4. In a device of the character described a pair of chambers. diaphragmsseparating said chambers, a valve in one of said chain- ",ers forregulating the supply of refrigerating fluid, a stem formed on saidvalve and bearing against one of said diaphragins, a lever pivotedintermediate its ends in the other of said chambers, the ends of saidlever bearing against said diaphragms. means for varying the fulcrum ofsaid lever. and means for supplying a thermostatic fluid to the secondof said chambers.

5. In a device of the character described, a pair of chambers, a pair ofdiaphragins separating said chambers. one of said diaphragnis beingsubstantir-illy larger than the other, a valve in one of said chambershaving its stem bearing against the smaller of said diaphii'agms, adifferentially pivoted lever in the other of said chambers, the freeGEORGE F. KNOX.

